81 x 9 = 801. What must you do to make the this equation true?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

Can you find out which triangle will have a bigger area among the following?
1. A triangle with sides 300, 400 and 500
2. A triangle with sides 300, 400 and 700

A man is walking down a road with a basket of eggs. As he
is walking he meets someone who buys one-half of his eggs
plus one-half of an egg.
He walks a little further and meets another person who buys
one-half of his eggs plus one-half of an egg.
After proceeding further he meets another person who buys
one-half of his eggs plus one half an egg. At this point, he
has sold all of his eggs, and he never broke an egg.
How many eggs did the man have to start with?

A man had five children. He had $100 with him to give to his children. He decided to start with the youngest child and then give $2 more than each younger child to his next elder child.

For example, if he gives $x to the youngest child, he will give $(x+2) to the next one, $[(x+2) + 2] to the next one and so on.

Can you find out how much did the youngest one receive?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?